Arrangement at telescopic lifting beam

ABSTRACT

Two telescopic lifting beams are loaded in their protruded position and are driven from a retracted position to a protruded position. In order to improve the bending strength of the lifting beams, the lifting beams are surrounded by two telescopic tubes ( 4, 5 ), one ( 4 ) of the tubes being fixed to the outer end ( 6 ) of the telescopic first lifting beam ( 1 ) and is slideable on the second telescopic tube ( 5 ), which extends inwardly on the second lifting beam ( 2 ).

[0001] This invention relates to an arrangement at at least twotelescopically protrudable lifting beams, which are loaded in theirprotruded position and which are driven in an optional way from aretracted position to a protruded position.

[0002] Lifting beams of this type are used, e.g. within the medicalservice for lifting means, when a person is being lifted from a sittingposition to a standing position or from one place to another. Telescopiclifting beams of this kind are also used for other lifting purposes forpatients.

[0003] The lifting beams are normally loaded in their longitudinaldirection and they are designed to meet such a load. The lifting beamscan be driven hydraulically via gears or manually using rope-drivingmeans or with the help of a crank means.

[0004] It has now shown, e.g. within the medical service, that thelifting beams unintentionally have been loaded by bending when thetelescopic beams are in their protruded position in relation to eachother, which have lead to that the outer lifting beam has been bent inthe area where it protrudes out of the outer end of the first liftingbeam. The object of the invention is to increase the strength of thelifting beams when they are in their protruded position and that this isaccomplished by simple means, which are cheap. The reinforcement is easyto apply on existing lifting beams without any complicated amendments oftheir design.

[0005] In order to reach this object the invention has been given thecharacteristics, which are stated in the following claims.

[0006] An embodiment of the invention will now be described by referenceto the drawings.

[0007]FIG. 1 is hereby a side view, partly in a longitudinal section, oftwo telescopic lifting beams in their protruded position.

[0008]FIG. 2 is partly a longitudinal section of the telescopic beams intheir retracted position.

[0009]FIG. 3 is a longitudinal section of an area depicted by the arrowA in fig./.

[0010] The arrangement shown in FIGS. 1 and 2 comprises a lifting beam1, which is telescoping in a second lifting beam 2, being fixed to adriving means 3 which displaces the first lifting beam 1. The drivingmeans 3 can be any known engine as e.g. a hydraulic engine or a gearmotor, which drives the lifting beam 1 telescoping in the lifting beam2. The lifting beams are loaded when the lifting beam 1 is protrudingout of the lifting beam 2 in the position shown in FIG. 1. The liftingbeams 1 and 2 are surrounded by two telescopic tubes 4 and 5, the firsttelescopic tube being displaceable over the second telescopic tube 5.FIG. 1 shows that the telescopic tubes 4 and 5 are in their mostprotruded position while FIG. 2 shows that the telescopic tube 4 isretracted on the second telescopic tube 5 over half of the length of thesecond telescopic tube 5. The first telescopic tube 4 is fixed to theouter end 6 of the first lifting beam 1 by means of a means of anattachment 7. The telescopic tube 4 has a first coupling part 8 at itsinner end, see FIG. 3. The second telescopic tube 5 has a secondcoupling part 9 at its outer end, see FIG. 3. The two coupling parts 8and 9 work in such a way that when the telescopic tube 4 is moving withthe telescoping beam 1, the coupling part 8 is hitched by the couplingpart 9 so that the second telescopic tube 5 follows the first telescopictube 4. When the telescopic tube 4 moves in the opposite direction, thecoupling part 8 moves away from the coupling part 9 and the secondtelescopic tube 5 is pushed inwards on the second lifting beam 2 by thatthe attachment means 7 will abut the outer end 10 of the secondtelescopic tube, see FIG. 3.

[0011] As can be seen from FIG. 3 there is a bearing ring 10 attached tothe outer end of the second telescopic tube 5. The inner periphery ofthis bearing ring contacts the outside of the first lifting beam 1 andslides along the lifting beam 1. By this, the outer end of the secondtelescopic tube 5 is supported by the lifting beam 1. The lifting beam 2has a bearing tube 11 at its outer end, the second telescopic tube 5slides on the bearing tube 11. The second telescopic tube 5 has abearing ring 12 at its inner end, which bearing ring slides with itsinner periphery edge on the lifting beam 2. When the second telescopictube 5 is in its protruded position according to FIG. 1, the telescopictube 5 is stopped by a stop-ring 13, which is attached to the liftingbeam 2. The stop ring may also serve as a guiding means for the secondtelescopic tube 5.

[0012] When the arrangement is in the position shown in FIG. 1, thesecond telescopic tube 5 will act as a support for the lifting beam 1via three points. The first support point is in the area shown by arrowA, the second support point is in the area of the bearing tube 11 andthe third support point is at the area of the second bearing ring 12. Bythis the lifting beam 1 will be reinforced against bending in the areaof the tube 11.

[0013] The invention has been described above in connection with twotelescopic lifting beams but the same reinforcement means can bearranged for e.g. three telescopic lifting beams. Further, there is apossibility to make the telescopic tube 5 sliding on the lifting beam 2along its complete length, thus without the second bearing ring 12 andthe tube 11, which means that according to FIG. 1 the telescopic tubeslides with half of its length on the lifting beam 2. FIG. 1 also showsthat the length of the first telescopic tube is about half the length ofthe first lifting beam in its protruded position while the secondtelescopic tube 5 has a length which corresponds to about half of thelength of the second lifting beam 2. The length of the telescopic tubesmay of course be arranged to what is needed but the important is thatthe second telescopic tube is of such a length that it supports theouter lifting beam at a point which is far away from the outer end ofthe inner lifting beam 2.

1. Arrangement at at least two telescopic lifting beams, which areloaded in their protruded position and which are driven from retractedto protruded positions with any suitable means, characterized by, thatthe lifting beams (1, 2) are surrounded by at least two telescopic tubes(4, 5), one of which being attached to the outer end (6) of the firstlifting beam (1) and being telescoping on the second telescopic tube(5), which extends inwards over the second lifting beam (2), that thereis a first coupling means (8) between the tubes (4, 5) at the inner endof the first telescopic tube (4) and a second coupling means (9) at theouter end of the second telescopic tube (5), said coupling means (8, 9)preventing the telescopic tubes (4, 5) to be drawn apart in theirprotruded position but allows the tubes to be retracted over each other,and that the second telescopic tube (5) has a first support point at itsouter end in the form of a ring (10) which slides over the firstprotrudable lifting beam (1) and bear against the second lifting beam(2) at least at the outer end of the lifting beam (2) and also at itsinner end.
 2. Arrangement according to claim 1, characterized by, thatthe support between the second telescopic tube and the second liftingbeam is formed by fixed rings (11, 12) or tubes on the second liftingbeam (2).
 3. Arrangement according to claim 2, characterized by, thatthe fixed ring (12), which forms a bearing at the inner end of thesecond telescopic tube (5), also forms a part of a coupling, whichlimits the movement of the tube outwards on the second lifting beam. 4.Arrangement according to claim 1, characterized by, that the firstbearing point (at A) of the second telescopic tube (5) is placed on themiddle of the first lifting beam (1), when the first lifting beam is inits protruded position, whereby the inner end of the second telescopictube (5) is at about the middle of the second lifting beam (2).